Refrigerated showcases



L. K. QUICK REFRIGERATED SHOWCASES Filed May 27, 1959 Nov. 22, 1960 MPS T IN1/EN TOR. 150 5751? z. @afge BY Y s. Z 117 mw 115 UI' WJ y Ill'. n nini.. .4:71

United States Patent REFRIGERATED SHOWCASES Lester K. Quick, 1963 W. 6th Ave., Eugene, Oreg.

Filed May 27, 1959, Ser. No. 816,282

8 Claims. (Cl. 62-150) The present invention relates to improvements in refrigeration cabinets and particularly of the kind used in stores in which customers are allowed to open a transparent door to gain access to food products on shelves in the cabinet.

In cabinets of this character it is desirable, of course,

that the transparent door remain transparent, and not become fogged or iced, as a result of opening and closing of the door since otherwise the obvious purpose of the transparent door is defeated. f It is therefore an object of the present invention to provide an improved refrigeration cabinet having a transparent door which does not become fogged, clouded or iced as a result of repeated opening and closing of the same.

Another object of the present invention is to provide an improved refrigeration system in a display cabinet.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. This invention itself, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in connection with the accompanying drawings in which:

Figure l is a transverse sectional View through a cabinet embodying features of the present invention and shows refrigeration apparatus in the bottom thereof somewhat in schematic form.

Figure 2 is a section like Figure l but illustrates a vane positioned for achieving a defrost condition.

Y' Figure 3 is a section similar to Figure 1 and illustrates the cabinet with the door open to illustrate the manner in which one of the ducts tends to become iced or frosted.

Figure 4 is a sectional View like Figure 1 but illustrates a modified form of the present invention.

' Figure 5 is a schematic representation of electrical apparatus for accomplishing periodic defrosting.

Figure 6 illustrates the present invention incorporated in a open-top refrigerated case.

Y Figure 7 illustrates a refrigeration system which incorporatesY a diaphragm or vbellows for controlling the valve 70. t

Referring to Figure 1, there is shown a refrigeration cabinet l'havin'g' an outer wall 11 and an inner wall 12 'with heat insulation material 13 therebetween, following conventional construction practices` Such cabinet 10 is provided with an opening 14 which is normally closed by a transparent door of glass or the like. The glass 16 is retained in a frame member 17 which abuts a resilient or elastic seal 18 snugly tted on an extension 19 of the frame of the cabinet 10 so that normally with the door closed as shown in Figure l, a prospective customer may view refrigerated food products mounted on any one of shelves 20 which, for purposes of illustration, are shown herein as being four ,in number.

Preferably located at the bottom of the cabinet, as diagrammatically illustrated in Figure l, is the refrigeration coil illustrated herein as the evaporator 22 and the circulating fan 2S. It is understood, of course, that the evaporator coil 22 is operatively connected in a conventioual refrigeration system with a compressor, its motor and receiver coil all arranged outside of the refrigerated cabinet. Normally, as indicated by the arrows in Figure 1, the cold air chilled by the refrigeration apparatus by evaporator 22, after passing through the evaporator 22 where it is chilled, is circulated by the pump 28 upthrough the vertical channel or duct 32 and upper horizontal channel 32A as indicated by the arrows 33, 34, 35 and 36.

It is noted that the ducts 32 and 32A are interconnected and that the discharge point at the upper horizontally extending duct 32A is above and closely adjacent to the top edge of the door 15 so that there is a stream of cold air passing downwardly and parallel or tangential to the plane of the glass door 16 as indicated by the series of arrows 37, 38, 39 and 40. This last series of arrows deiines a path which extends between the door 15 and the outer edges of the shelves 20, the edges of the shelves 20 being set back suiciently to allow this cold ow of air past the glass door 16. This ow of air is reversed `atter it reaches the bale or floor 42 of the storage portion of the cabinet and then is either deflected upwardly by the same or there is an up'- ward ow of air as a result of its being previously hea-ted and such upward ow is indicated generally by the series of arrows 44, 45, 46, 47 and 49 which defines a path leading to the upper end of the inner duct 50.

This duct 5t) extends generally parallel with the previously mentioned duct 32 and is insulated therefrom by insulating material 53. This air owing downwardly through the duct 5G, as indicated by the arrow 55, enters the lower chamber 56 dened generally by the lower floor or bale 42 and the outer wall of duct 58. This air is again chilled in evaporator 22 and recirculated as described above. Y It will thus -be seen that there has been provided an arrangement wherein a flow of cold or `chilled air tangential or parallel with the glass door 16 has been provided along substantially the full length thereof so as to facilitate the removal of ice crystals which might form on the door when it is opened. This condition is assured to a large extent by the position of the discharge end of the upper duct 32A which discharges a stream of cold and chilled air into the cabinet at a point closely adjacent to and above the upper edge of the door 15. While the shelves 20 are preferably of perforated shelving material to allow flow of air therethrough as indicated generally by the series of arrows 45-48, the arrangement is such that this general pattern of cold air flow is not disturbed appreciably when lthe shelves 20 are loaded with food products.

As a result of opening and closing the door -by customers at various times, the duct 50, and particularly 'the upper end thereof, has a tendency to become iced or frosted. When the door 15 of the cabinet 10 is in its open position there is a ow of air of much higher temperature from the outside of the cabinet in the direction indicated by the series o-f arrows 6l), 61, 62 and 63 into the upper end of duct Si). The moisture in this entering air tends to become condensed with the result that there is a tendency for ice or frost to form in this duct Sti. To prevent excessive formation of frost or ice, there is provided in accordance with another phase of the presen-t invention means to change the air flow circulation pattern in the cabinet. For this latter purpose, as illustrated in Figures 1 3, there is provided a pivoted valve element or baille which is pivoted about its central axis 71 and which, as shown in Figures l and 3, normally forms a portion of a wall of duct 32 to assure the flow pattern debellows or as illustrated by an electric solenoid 73 operating the Ibaifle 70 through a lever 74. When a diaphragm or bellowsis used, the same is made responsive to pressure inthe refrigeration system Vsuch that on defrost, at which time a relatively large pressure exists, such pressure is active to cause the baille 70 to move to its position shown in Figure 2 `to directly interconnect the ducts 32 and 50. Such lever 74, for example, may have one of its ends yrigidly attached to the shaft 71 which is journalled vfor rotation on-thecabinet; and the other end of the lever 74 may Ibe loosely connected to the armature extension 73A of the solenoid. The Asolenoid is shown in its deenergized position in Figure l and when the same is energized, it causes the baille 7i) to -be moved to its position illustrated in Figure 2 wherein opposite ends of the same contact the walls 50A, 32B of ducts 5i) and 32 respectively so as to effectively short-circuit the ilo'w of air into the duct 50, such flow being in this case represented by the series of arrows 80, 81, 82, 83. When this condition illustrated in Figure 2 occurs, i.e. the solenoid 73 (Figure l) is energized, a heater 90 located at the bottom of the cabinet and in communication with the chamber 56 is also ener-gized to produce a heating of the air which ows in the pattern illustrated by the arrows Sil-S3 in. Figure 2. This flow ofV heated air through the upper end and along the length of duct 55 clears the same of any frost, ice or moisture. It Will fbe understood, of course, that the heater 90 and solenoid 73 are energized periodically, i.e. are not continuously energized and that its energization may `be controlled as, for example, a time clock, by outside temperature conditions, -by the number of times the door 15 has been opened'or by any other suitable control.

Figure 5 illustrates generally how this is accomplished, it being noted that the solenoid 73 and heater 90 each have an opposite one of their terminals connected to a source of voltage 92 through a switch 94. This switch 94 may be controlled using any one of the expedients indicated above.

lIn the modiiied arrangement illustrated in Figure 4, a different form of movable baille element 95 is provided for directing the How of heated air from duct 32 into duct 50.

InV normal operation this movable bathe 95, which is pivotable about the axis 96, extends downwardly as indicated 'by the dotted lines to allow the flow of cold air past the door in the same manner as indicated in Figure 1. However, when the solenoid 173 (corresponding to 73 in Figure l) is energized, the baille 95 is pivoted upwardly to its full-line position illustrated in Figure 4 wherein such bathe 95 extends generally horizontally and thus directs a iiow of air in the direction indicated b-y the arrows 97, 9S, 99 into the upper end of duct 50. This path deiined by the arrows is in the form of a stratified layer of air and since the air at :this time is heated, the same is ger'ierallyl stratified at the upper end of the cabinet Vas indicated.

This solenoid 173 is energized simultmeously with the heater 9i) as explained above in connection with Figurel.

Thus, it will be seen from the two forms of the invention described herein that the upper end of conduit 50 and the length of conduit Sil may be periodically defrosted orde-iced so that the primary purpose of a clear glass door 15 may be continuously maintained, such primary purpose being accomplished by directing'a stream of cold air from a point above andimmediately adjacent the upper edge of the door 15 so as to produce a ow of cold air past the door either tangential or parallel with respect thereto to Vmaintain the same clear.

:It will be understood, of course, that the present inven tion may be incorporated not only in thefreach in type of cabinetshown Ikin the drawings, but is also applicable `toj conv-entional open-top ice cream and frozen food. cases.

Figure 6 illustrates an open-top refrigerated chamber or case having an insulated forward wall 125, an'insulated rear wall 126 and a bottom shelf 133 upon which refrigerated products are stored. Access is had to such products through the open top 130 of the case. In this instance the refrigerated air supply duct 132 (corresponding to 32 in the previous figures) is located forwardly and the return duct 150 (corresponding to duct 5i) in the previous figures) is disposed rearwardly of duct 132, and here again insulating material 134 separates the two.

The normal flow of refrigerated ,air is indicated by the series of arrows 135 in Figure 6, it being noted that refrigerated air flows up the duct 132 and is guided by the series of vanes 137 so thatthe same may flow eciently in a direction which extends generally horizontally at the time the refrigerated ahleaves the duct 132. Due to the fact that such air is refrigerated, it tends to stratify and in doing so, it tends to flow downwardly to a certain degree, as indicated by the arrows 135, from the rear to the forward wall of the chamber during which time, of course, the air becomes heated and as a result tends to rise. The result is that the refrigerated air, after heating, is returned through the return duct 150. In order to -defrost the duct 150, the valve 170 (corresponding to the valve o-r baffle 70 in the previous figures) is provided. During the defrost cycle this baffle 170 is positioned to interconnect the ducts 132 and 150 as indicated in dotted lines in Figure 6.

-Figure 7 illustrates generally a refrigeration system arranged to control the valve 70 illustrated in the previous gures. As shown, the system includes a conventional compressor 110 operatively connected in conventional rnanner to a condenser 112, receiver 113, evaporator 22, the evaporator being connected to thefoutletrof the receiver through a conventional expansion valve 11-5. This expansion valve 115 is responsive to temperature in the suction line 117 which extends fromV the evaporator 22 back to the inlet of the compressor 110. A so-called hot gas line 118 with a solenoid valve 119 therein extends from the outlet of the compressor 110 to the inlet of therevaporator 22, such line 118, however, being opentonly on defrost by operating the solenoid valve 119 to its open position. At the time this solenoid valve 119 is open, a relatively high pressure is` de veloped in the evaporator 22 and such pressure is transferred through conduit 120 to thebellows 122 for operating the previously mentioned diverting Vvalve 7.0.

It is noted that in changing from the normalA refrigeration cycle to the defrost cycle, the, pressure in the evaporator 22 builds up rapidlyA and such .pressureV is,` of course,` transferred through the conduit 120 to the bellows 122 to move the valve 70 to its closed positionrshown in Figure 2. At .the end of the defrost cycle, Mat ,which time the solenoid valve 119 is de-energized to allow the valve 119 to close, the pressure in theevaporator 22falls slowly or gradually, whichY means thata timev delay exists between the closing .of the solenoid valve 119 and the opening of the baille allowing time for theevaporator 114 to pick up the excessive high humidity ,that `is developed in the chamber in which the evaporatoris enclosed. This chamber includes conduits 32 50 and 56. This humidityvotherwise would bercarried into-the food compartment where it would deposit.v as frost onl the product.

ln defrosting the conduits 32 and v50, the same may be accomplished in some cases by heat developed during the defrost cycle. Such heat may result upon energizing the heater which, as shown in Figure 7, is energized at the same time the hot gas solenoid 119 ispenevrgized. in other cases it may be desirable not to use the heater 93 but to circulate through. conduits 32 and 50 air which has been heated by hot gases in theevaporator during the defrost cycle.

It is understood, of course, that defrosting of the conduits 32 and 59 may be accomplished using the. heater 90 alone, using heat developed solely in the refrigeration system during the defrost cycle by the hot gases, or a combination ofthe same.

While the particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall Within the true spirit and scope of this invention.

I claim:

1. A refrigerated chamber having a front wall and a back wall, said front wall being defined by a transparent door mounted on said chamber, a pair of ducts mounted adjacent said back wall in said chamber with one of said ducts extending forwardly towards said front door and terminating at a region above said front door, refrigeration apparatus in communication with said ducts, both of said ducts normally terminating at a region close to the top of said chamber with one of said ducts being a cold air supply duct and the other duct being a warm air duct and with said other duct terminating in a region near the back wall of said chamber, said supply duct being so arranged that the cold air leaving the same moves generally parallel with and tangential to the plane of said transparent door, heating apparatus normally ineffective, control means effective when operated to place said supply and return ducts in communication, and means operating the last mentioned means and said heating means together.

2. A refrigerated chamber having a Wall thereof dened by a transparent door, a refrigeration system including a cold air supply duct in said chamber, said duct having its supply end terminating in a region above said door to normally provide a flow of cold air generally parallel with and tangential to the inner surface of said transparent door, said refrigeration apparatus incorporating a return duct having its inlet located Within and near the top of said chamber, cold air flowing downwardly past the door to the bottom of said chamber and then returning upwardly and being discharged into the opening to said return duct near the upper end of said chamber, means effective when operated to place the outlet of said supply duct in communication with the inlet of said return duct, and means eifective when the last mentioned means is operated to produce a flow of warm air through said supply and return ducts without the last mentioned warm air passing through any substantial portion of said chamber.

3. A refrigerated chamber having a transparent door forming a portion of one wall thereof, refrigeration apparatus incorporating a cold air supply duct and a warm air return duct, said supply duct having its outlet disposed in said chamber and arranged to direct a ow of cold air downwardly past the inner surface of said transparent door, said return duct having its inlet in the upper portion of said chamber and normally receiving said cold air after it moves downwardly past said door and then moves upwardly to the location of said inlet of said return duct, means normally ineffective, but effective when operated, to effectively place the outlet of said supply duct in communication with the inlet of said return duct,

and means for producing a ow of warm air through said supply duct and said return duct when the last mentioned means is operated without the last mentioned warm air passing through any substantial portion of said chamber.

4. A refrigerated cabinet having a transparent door forming a portion of a wall of said cabinet, said door defining generally the front wall of said cabinet, said cabinet having a rear wall, a pair of ducts mounted in said cabinet and extending generally upwardly parallel with said rear wall of said cabinet, both of said ducts terminating in the region of said upper portion of said cabinet and generally at a region located above said door, a plurality of vertically spaced perforate shelves mounted in said cabinet and generally accessible when said door is open, refrigeration apparatus located in the bottom of said cabinet and effective to normally supply cold air to the lower end of one of said ducts and to receive returning warm air from the lower end of the other duct, said one duct comprising a cold air supply duct and said other duct comprising a Warm air return duct, the outlet of said supply duct being positioned in the upper portion of said cabinet to produce generally a flow of cold air downwardly past the inner surface of said door with said air then returning upwardly through said perforate shelves to the top portion of said cabinet where the same enters the inlet to said return duct, means normally ineffective, but effective when operated, to effectively place the outlet of said supply duct in communication with the inlet of said return duct without the air in such latter case passing through the perforate shelves, and means effective when the last mentioned means is operative to produce a iiow of warm air which flows through said supply duct and immediately returns through said return duct without passing through a substantial portion of said cabinet.

5. A refrigerated chamber having an opening thereto, a pair of ducts mounted adjacent said opening, refrigeration apparatus in communication with said ducts, both of said ducts normally terminating at a region close to and adjacent said opening with one of said ducts being a supply duct and the other being a return duct, said supply duct being so arranged that the cold air leaving the same moves generally parallel With the plane of said opening, heating apparatus, normally ineffective, control means effective when operated to effectively place said supply and return ducts in communication, and means operating the last mentioned means and said heating apparatus together.

6. A refrigerated chamber as set forth in claim 5 in which said chamber comprises an open-top case.

7. A refrigerated chamber as set forth in claim 5 in which said opening is closed by the transparent door.

8. An arrangement as set forth in claim 5 in which said control means comprises means responsive to pressure developed in the refrigeration system.

References Cited in the le of this patent UNETED STATES PATENTS 1,940,515 Sundling Dec. 19, 1933 2,443,342 Colvin June 15, 1948 2,863,300 Murphy Dec. 9, 1958 

